1. Field of the Invention
The present invention relates, in general, to cooking apparatuses. In particular, the invention relates to a microwave cooking apparatus wherein a magnetron for generating microwaves and a rotatable device for reflecting the microwaves from the magnetron into a cooking chamber are employed.
2. Description of the Prior Art
As is well known, microwave cooking apparatuses, such as microwave ovens, typically include a fan device for cooling electric components, such as, e.g., a magnetron, a transformer, etc., and for ventilating the cooking chamber. The microwave cooking apparatus also generally includes a rotatable reflector arranged between the magnetron and the cooking chamber for reflecting microwaves from the magnetron. The reflector is rotated by the force of cooling air generated by the fan device. Thus, the microwaves reflected by the reflector are uniformly fed to the cooking chamber.
A microwave cooking apparatus of the type described above is disclosed in Japanese Utility Model Laid-open Publication No. 1159/1978, filed June 23, 1976 in the name of Ichiro Hori, and entitled HIGH FREQUENCY HEATING APPARATUS. In this prior art, a reflecting chamber in which a rotatable reflector is disposed is provided on a cooking chamber. Some of the cooling air generated by a fan device is directed to the reflecting chamber. The remaining cooling air is supplied to a magnetron for cooling the magnetron, and then is fed to the reflecting chamber.
Those two cooling airs described above are re-joined in the reflecting chamber so as to rotate the reflector. After that, the re-joined air enters into the cooking chamber, and then it is discharged from the chamber. At this time, the vapor and the grease generated from food during cooking may be exhausted from the cooking chamber together with the cooling air.
In the above-described prior art, a suitable amount of the cooking air generated by the fan device is supplied to the reflecting chamber for rotating the reflector, and then is fed to the cooking chamber. The remaining cooling air also is supplied to the cooking chamber through the magnetron and the reflecting chamber. Therefore, the pressure of the cooling air decreases during the migration described above. As a result, the vapor and the grease from food in the cooking chamber may not be sufficiently exhausted from the cooking chamber because of the low pressure of the cooling air. Thus, a large capacity fan device is needed in this prior art apparatus if the vapor and the grease in the cooking chamber are to be discharged sufficiently. In addition, in this prior art apparatus, recirculation of the exhausted cooling air may occur because its exhaust port is provided close to the intake port.